Space microbes aren't so alien after all

The International Space Station photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking. Credit: NASA/Roscosmos

Microbes stranded in the International Space Station (ISS) are just trying to survive, man.

A new Northwestern University study has found that—despite its seemingly harsh conditions—the ISS is not causing bacteria to mutate into dangerous, antibiotic-resistant superbugs.

While the team found that the bacteria isolated from the ISS did contain different genes than their Earthling counterparts, those genes did not make the bacteria more detrimental to human health. The bacteria are instead simply responding, and perhaps evolving, to survive in a stressful environment.

"There has been a lot of speculation about radiation, microgravity and the lack of ventilation and how that might affect living organisms, including bacteria," said Northwestern's Erica Hartmann, who led the study. "These are stressful, harsh conditions. Does the environment select for superbugs because they have an advantage? The answer appears to be 'no.'"

The study was published today (Jan. 8) in the journal mSystems. Hartmann is an assistant professor of environmental engineering in Northwestern's McCormick School of Engineering.

As the conversation about sending travelers to Mars gets more serious, there has been an increasing interest in understanding how microbes behave in enclosed environments.

"People will be in little capsules where they cannot open windows, go outside or circulate the air for long periods of time," said Hartmann. "We're genuinely concerned about how this could affect microbes."

The International Space Station photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking. Credit: NASA/Roscosmos

The ISS houses thousands of different microbes, which have traveled into space either on astronauts or in cargo. The National Center for Biotechnology Information maintains a publicly available database, containing the genomic analyses of many of bacteria isolated from the ISS. Hartmann's team used that data to compare the strains of Staphylococcus aureus and Bacillus cereus on the ISS to those on Earth.

Found on human skin, S. aureus contains the tough-to-treat MRSA strain. B. cereus lives in soil and has fewer implications for human health.

"Bacteria that live on skin are very happy there," Hartmann said. "Your skin is warm and has certain oils and organic chemicals that bacteria really like. When you shed those bacteria, they find themselves living in a very different environment. A building's surface is cold and barren, which is extremely stressful for certain bacteria."

To adapt to living on surfaces, the bacteria containing advantageous genes are selected for or they mutate. For those living on the ISS, these genes potentially helped the bacteria respond to stress, so they could eat, grow and function in a harsh environment.

"Based on genomic analysis, it looks like bacteria are adapting to live—not evolving to cause disease," said Ryan Blaustein, a postdoctoral fellow in Hartmann's laboratory and the study's first author. "We didn't see anything special about antibiotic resistance or virulence in the space station's bacteria."

Although this is good news for astronauts and potential space tourists, Hartmann and Blaustein are careful to point out that unhealthy people can still spread illness on space stations and space shuttles.

"Everywhere you go, you bring your microbes with you," Hartmann said. "Astronauts are exceedingly healthy people. But as we talk about expanding space flight to tourists who do not necessarily meet astronaut criteria, we don't know what will happen. We can't say that if you put someone with an infection into a closed bubble in space that it won't transfer to other people. It's like when someone coughs on an airplane, and everyone gets sick."

More information:
"Pangenomic approach to understanding microbial adaptations within a model built environment, the International Space Station, relative to human hosts and soil" DOI: 10.1128/mSystems.0028-18

Citation:
Space microbes aren't so alien after all (2019, January 8)
retrieved 25 May 2019
from https://phys.org/news/2019-01-space-microbes-alien.html

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User comments

Ohh! You terrible people! Spoiling the hysterical delusions of the panspermia cult & other comicbook enthusiasts.

& by "hysterical" I mean hysterically funny!

A common misconception is that the International Space Station is floating about in Outer Space. No, it's safely tucked in a tight orbit, close around the Earth. Shielded by the Magnetospgere.

Babysteps... Now I am no fan of long-term Human Space Travel. But it is interesting how the micro-bugs are adapting to their unforeseen environment.

It will be interesting over the years to come, comparing the wild bug stowaways aboard ISS, against the laboratory bugs versus the earthside bugs, Especially if sustained rates of reproduction can be established?

1. While there is no single agreed upon definition of what constitutes 'Outer Space', the definitions that are typically used would place anything in orbit around the Earth as being in outer space. The presence of the magnetosphere is irrelevant, particularly since its not a static feature. If your's is the definition we're using, than the Moon would periodically pass in and out of outer space as its orbit brings it through Earth's magnetotail.

2. The discoveries reported in this article have absolutely nothing to do with the validity of panspermia. As much as you like to insult the subject as a whole, you rarely address articles which actually discuss panspermia.

Your "opinion" is completely worthless, rather than valid, because it assumed that there was a in fact single definition of 'Outer Space'.

Panspermia is not a belief, it is a possible scenario for the origins of life on given worlds, and one we cannot currently dismiss as is true with all other theories explaining the origin of life on Earth.

Given that you cannot or refuse to acknowledge the difference between beliefs and a proposed natural phenomenon, I'd hazard a guess and say you're not really up to, "debate & clarify" anything in particular because your reasons for dismissing panspermia are irrational to begin with. Dismissing topics out of hand because of your personal incredulity is fallacious.

Comparing panspermia to flat Earth is a bald false equivalency. We can measure the shape of the Earth and have so for centuries, but we cannot do the same for life's origins.

Admitting that panspermia is valid has nothing to do with making, "woocultists" happy. It's recognition of the reality that actual scientists have demonstrated panspermia is valid and regularly publish discussions of the topic in refereed publications. Heck, even War and Brownlee's book, "Rare Earth" seriously and very favorably mentioned interplanetary and interstellar panspermia. Are we to consider them "woocultists" now?

You could keep going like you are all day, but that would just be a satisfying way of proving my point yet again. As I wrote before: Your reasons for dismissing panspermia are irrational to begin with. Nothing that you've written is anything more than juvenile rhetoric. If anything, your attacks on biologists reminds me of people attacking climate scientists.

DS, considering that organisms can survive travel through space? First, where did they originate & how did they escape to go star-hopping? With exactly the right survival skills? What do they need a planet for?

As for evidence that extremophiles are not super-bugs? Try finding any on the Antarctic High Plateau.

& puh-leeze! Do not mention superman's fortress of solitude.Hey! I asked you not to mention the SS FOS. Oh wait, I meant for you not to mention Niagara Falls!

"Slowly he turned... step by step"

As for the wildcatters staking claims to the outside of the ISS?I suspect they exited the station after it reached orbit.

Wiggling their way outside through deteriorating port seals & other microscopic imperfections. As the ex-bugs are to be found around those seals. Taking advantage of leaking air & water. Maybe they are not voluntary but shoved out by the air pressure differential? & now can't get back in?

There actually are bacteria which live in the High Plateau. From Michaud et al.'s, "Snow Surface Microbiome on the High Antarctic Plateau (DOME C)" PLOS One 2014, "These permanently frozen environments harbor diverse, viable and metabolically active microbial populations that represent almost all the major phylogenetic groups." While the density of life on the High Plateau is expectedly low, life nonetheless endures in the form of indigenous organisms and hardy transplants. Indeed, Michad et al. noted that this research was of particular value to astrobiology, as parts of Antarctica are good analogue to well known extra-terrestrial environments.

More relevant to panspermia is the reality that many organisms can slow down their metabolism and remain dormant but alive for centuries and perhaps even thousands of years. The discovery of such organisms is probably the single most important reason panspermia remains frequently published in scientific literature.

Belief has nothing to do with it. I am accepting the scientific consensus that panspermia is still valid. While there isn't any evidence of a particular form of panspermia, this is also true for abiogenesis as well as a great many still existing astronomical phenomenon ala dark matter, galaxy formation, etc.

It's pretty obvious here that you were never really focused on trying to understand the science of panspermia. The few times you attempt to address it (when you move outside your comfort zone of lazy insults), you make vague citations with material that you didn't even bother to skim through per the High Plateau.

guess I did a lousy job of admitting that I was wrong?On the subject of sustained populations of Earth micro-organisms being found on the Antarctica High Plateau.Because there is evident evidence presented.

Yet I refuse to budge on what I consider panspermia crankery.Cause, no evidence has been offered to date, only supposition for the reality of alien bugs in space.Or, anywhere else for that matter.

The guesstimates & speculations are not evidence. It will take an empirical effort, supported by top-notch researchers to, convince me otherwise.

You didn't admit to anything in particular other than claim you needed to reconsider your opinion.

The real problem here is that you can't admit your entire understanding of the subject is categorically wrong. Evidence has been offered that it could occur (extremophiles, cryobiology, etc.). Not the same as evidence that it did at the exclusion of all other possibilities, but again, this is often the case with science and not the point anyone is making. That's why we get competing scientific models all the time.

The argument you're making (it's, "only supposition") is the exact same tired argument Young Earth Creationists make when they're dismissing abiogenesis as a whole. Indeed, the TalkOrigins Archive even has it listed as Claim CB05: "Abiogenesis is speculative without evidence." To quote the page's response:

"Investigating the unknown is what science is for. Speculation is part of the process. As long as the speculations can be tested, they are scientific."

"Investigating the unknown is what science is for. Speculation is part of the process. As long as the speculations can be tested, they are scientific."

Have you been holding out on us? Are you conducting secret tests? & not shared the results with the rest of us? Specifically, which of your speculations have you proven?

Or, by the standard set by the paragraph you provided? The untested speculations are not scientific.

As for extremophiles. A good point for you, that common marine micro-organisms survive if not thrive in the surface snow. Have been joined by Human-borne bugs contaminating the scene.tps://en.wikipedia.org/wiki/Antarctic_Plateau#Fauna

Again, your entire understanding of the subject is categorically wrong. Theories in science can never be proven to begin with, and I have always maintained that panspermia is simply a valid scenario. I have never said that it did happen, merely that it could have. Again, the same is true for all models of life's origins. Singling out panspermia for a perceived fault that it in reality shares with all of its modern competitors is good evidence of your own ignorance of the subject and outright dishonesty.

As for evidence to its validity, again, we know that organisms can survive for extended periods of time in space within meteors (Horneck et al. "Protection of Bacterial Spores in Space, a Contribution to the Discussion on Panspermia" Origins of life and evolution of the biosphere 2001) and that interplanetary meteorites are a real phenomenon. Without further and more specific data, we simply can't exclude it as much as you like to in your attacks.

well Scolar, we are at the stage of declining costs for small rocketing experiments into Space. With a reasonable chance of retrieving the payloads afterwards.

Nothing fancy, a conservative effort such as the lifeforms experiment included on China's "Jade Rabbit".

A dozen or so attempts to breed populations of micro & not so micro organisms outside the Earth's gravity & the magnetosphere? Should provide some conclusive empirical evidence as to the survivability of biology in space.

Though I imagine, the really interesting science would come from inconclusive results. i.e. exposing assorted spores to vacuum & hard radiation, over decades?

To remove uncertainty, why not duplicate the experiments here on Earth. At least the vacuum & hard radiation parts? Differing results would challenge a lot of assumptions.

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